That first photo of McNaught is just amazing. (Could you imagine what it would be like if Earth passed through that tail, and the meteor superstorm that would result?)

The most recent comet I've seen was Holmes after its unexpected outburst. Was interesting to watch it night after night as it became larger and brighter, starting out as an extra "star" in the sky, then a vaguely fuzzy spot, and finally blowing out into an enormous diffuse sphere.

As for Hale-Bopp, the ISS wasn't up yet when it came by, but it was seen from Shuttle mission STS-82. There's an animation here but the quality isn't great. In my opinion the ISS photos of Lovejoy are much more impressive. Love the greenish air-glow, too.

This photo most closely resembles how I remember seeing Hale-Bopp. I hope 2012 S1 gives a similar performance.